Personal information management (PIM) service refers to a service enable a client to keep information in a mobile terminal consistent with a computer or a mobile network server in a mobile or cable way and inquire and manage the information by many kinds of terminals and access means.
The content of PIM generally refers to an address book, scheduling program, a memo pad and so on. The conventional PIM of a mobile terminal user is aimed at a local computer or a PC, which has nothing to do with a network. With continuous increase of a mobile terminal switching rate, it is necessary to provide a PIM service system at the mobile network side in order to enable the mobile terminal user to backup his own PIM data onto a server on the network side via an air channel, or synchronize the PIM information of a server on the network side to a mobile terminal so as to finally achieve the object of synchronizing the personal information on the a mobile terminal and a network server.
Because the address books on a current mobile terminal and a PC all adopts the VCard format defined by the international standard organization. However, in order to ensure the extensibility for the implementation by terminal A manufacturer, the criterion file defines very flexible format content and also defines a lot of fields which can be expanded by the terminal manufacturer. This results in inconsistency of many address book formats of terminal A currently. And the PIM service often has a situation that the content of terminal A is synchronized to the server and then is further synchronized onto terminal B, which results in the problem of address book data loss because of inconsistent formats.
In prior art, a method for solving the problem of data loss because of inconsistent formats is that a server stores the synchronization data of the terminal A and the data which can not be synchronized by the terminal B are till stored in the server. Superficially, this solution solves the problem of address book data loss but there are still many problems left.
For example, an address book of user A is as follows:
Wang Er's mobile phone: XXXX, office phone: XXXX, home phone: XXXX, facsimail number: XXXX
Zhang San's mobile phone: XXXX, office phone: XXXX, home phone: XXXX, facsimail number: XXXX
Li Si's mobile phone: XXXX, office phone: XXXX, home phone: XXXX, facsimail number: XXXX
As shown in FIG. 1, it is a Vcard structure mapped by an address book. The address book comprises many records. Each of the records further comprises many items For example, corresponding to the address book of the user A, all the information of Zhang San is one record in the structure. There are many items in the record, that is, Zhang San's mobile phone, office phone, home phone and facsimail number. In different terminals, the same item may adopts different combination identifier “attribute; parameter”. For example, one mobile phone may use an identifier of “TEL; Cell” or “TEL; Voice; Cell”, and the items supported by different terminals may also different. The inconsistency of terminal address book formats may produce the problem of information loss as follows:
(1) In different mobile terminal, the same item may use different combination identifiers of “attribute; parameter”. For example, in the terminal A, the item of “mobile phone” is identified by “TEL; Cell”. In the terminal B, the “mobile phone” is identified by “TEL; Voice; Cell”. The user synchronizes the address book of the terminal A onto the server. The server receives the synchronization content and stores the item of the mobile phone by “TEL; Cell”. When the user switches to terminal B and requests the server to synchronize the address book to the terminal, the server will still synchronizes the identifier of “TEL; Cell” to the terminal B but the terminal B can not recognize it, which results in information loss. Besides, under this circumstance, the server has to be able to recognize a one-to-many corresponding relationship between the item and all the combinations of “attribute; parameter”; otherwise, the server may also lose user data.
(2) The “attribute; parameter” corresponding to the items of some terminals is formed by adding some additional parameters with no impact to the items behind the “attribute; parameter”, such as a PREF parameter representing priority. The existing server does not process these parameters, which results in information loss because no suitable item can be matched or results in incapability of showing it on a website to the user. Although the server has stored the parameter information, when the user switches the terminal B and perform synchronization of the address book once again, the situation that these fields can not be recognized will also appear, which results in information loss.
(3) The items supported by different terminals may also be different. For example, the items supported by the terminal A are: item 1 (mobile phone), item 2 (office phone) and item 3 (home phone). However, the terminal B only supports the item 2 (office phone) and the item 3 (home phone). The user synchronizes the address book onto the server by the terminal A. The server receives and stores the synchronization content. When the user switches to the terminal B, the server will synchronized the item 2 and the item 3 to the user. However, the item 1 is only stored on the server. If the user modifies the item 2 or the item 3 of a record in the address book on the terminal B, the synchronization with the server will be executed. Because the existing synchronization operation aims at the record, the record in the server will be substituted and the item 1 in the original record will also be cleared consequently. When the user switches back to the terminal A and performs data synchronization again, the user can not get the information of the item 1 in the record.